Recently, there are increasing demands for further improvement of the processing performance of storage systems along with the enhancement of processing performance of processors and the advancement of data transfer technology. In order to improve the processing performance of the storage system, it is necessary to adopt the latest components and technology, enhance processors and other components, and improve the processing efficiency of data transfer that occurs within the storage system.
On the other hand, in order to follow the reduction of costs progressing in the whole storage system market, approaches are made to adopt the latest components and technology and the enhancement of components, but such approaches for enhancing the processing performance lead to increased costs, so that it is difficult to correspond to market trends. In order to realize both low costs and enhanced processing performance of storage systems, it is effective to improve the processing efficiency of data transfer.
Patent Literature 1 discloses an art for enhancing the processing efficiency of data transfer in a storage system. This patent literature teaches efficient use of channel access paths among channel I/F units, disk I/F units and shared memory units or cache memory units, thereby improving the memory access throughput, especially the access throughput to the cache memory.